Synthesis method of polymer complex crystal

ABSTRACT

Disclosed is a synthesis method for synthesizing in a short time and selectively a microcrystal of a polymer complex having three three-dimensionally and regularly arranged channels. 
     Specifically disclosed is a synthesis method of a polymer complex crystal wherein (1) a metallic solution, which is a mixture of zinc halide(II) and a solvent A that can dissolve the zinc halide, is mixed with (2) a ligand solution, which is a mixture of a tridentate ligand that has three coordination sites coordinated to zinc of the zinc halide and a solvent B that can dissolve the tridentate ligand, to be a single-phase solution, thereby synthesizing a microcrystal of a polymer complex having a three-dimensional coordination network formed by coordinating the tridentate ligand to the zinc and having channels that are three-dimensionally and regularly arranged in the three-dimensional coordination network.

TECHNICAL FIELD

The present invention relates to a method of synthesizing a crystal of apolymer complex having three-dimensionally and regularly arrangedchannels in a short time.

BACKGROUND ART

By allowing a mixture containing many kinds of compounds to be passedthrough, or in contact with, a material having a porous structure whichtakes a guest compound in, a specific compound can be selectively takenout. As such a microporous material, for example, a polymer complexhaving organic ligands complexed with a trans it ion metal, or zeoliteis known and used in many applications as a selective reversibleadsorbent, a catalyst carrier, etc.

SUMMARY OF INVENTION Technical Problem

A common method of synthesizing a microporous polymer complex is acounter diffusion method in which a solution containing a metallicspecies is gently brought into contact with a solution containing aligand so that the metallic species gradually reacts with the ligand atthe interface of the solutions, thereby growing a crystal of a polymercomplex slowly. Such crystal growth takes a long period of time such asone week or more. Therefore, although microporous polymer complexes havebeen expected to be used and applied for various purposes due to theirhigh functionality, it has been difficult to practically use them forpurposes where bulk synthesis is required.

In the research and development of microporous polymer complexes, theinventors of the present invention made a diligent study of the methodof synthesizing microporous polymer complexes and the method ofspecifying the structure of polymer complexes. As a result, they havefound out that contrary to their expectations, a single-componentmicrocrystal of a polymer complex having three-dimensionally andregularly arranged channels can be synthesized without taking, unlike inthe counter diffusion method, a long time to grow a crystal.

That is, an object of the present invention is to provide a synthesismethod for synthesizing a microcrystal of a polymer complex havingthree-dimensionally and regularly arranged channels in a short time andselectively.

Solution to Problem

The synthesis method of the present invention is characterized by that(1) a metallic solution, which is a mixture of zinc halide (II) and asolvent A that can dissolve the zinc halide, is mixed with (2) a ligandsolution, which is a mixture of a tridentate ligand that has threecoordination sites coordinated to zinc of the zinc halide and a solventB that can dissolve the tridentate ligand, to be a single-phasesolution, thereby synthesizing a microcrystal of a polymer complexhaving a three-dimensional coordination network formed by coordinatingthe tridentate ligand to the zinc and having channels that arethree-dimensionally and regularly arranged in the three-dimensionalcoordination network.

By mixing a nitrobenzene solution of2,4,6-tris-(4-pyridyl)-1,3,5-triazine with a methanol solution of ZnBr₂or ZnI₂ at room temperature and stirring the mixture for a short time,the inventors of the present invention has succeeded in obtaining asingle-component microcrystalline powder (that is, having the samecomposition formula and isomorphic crystal structure) of a polymercomplex in a much shorter time than that of the counter diffusionmethod, thereby completing the present invention.

According to the present invention, a crystal of a polymer complexhaving three-dimensionally and regularly arranged channels can besynthesized in a short time and in bulk quantity without taking a longtime to grow a crystal unlike in the counter diffusion method, which isa conventional method of synthesizing a polymer complex.

The step of mixing (1) the metallic solution with (2) the ligandsolution may be performed at room temperature.

Specific examples of the zinc halide (II) include zinc bromide (ZnBr₂),zinc iodide (ZnI₂).

Suitable examples of the tridentate ligand include one wherein thedirections of coordination bonds formed by the three coordination sitesthereof are present in almost the same plane, and one wherein the threecoordination sites are arranged radially from the center of thetridentate ligand at regular intervals.

Specific examples of the tridentate ligand include an aromatic compoundrepresented by the following Formula (1):

ArX—Y)₃  Formula 1

wherein Ar is a structure having an aromatic ring; X is a divalentorganic group or a single bond through which Ar and Y are directly boundto each other; Y is an atom having a coordination site or an atomicgroup having a coordination site; and a plurality of Xs contained in onemolecule may be different from one another, and a plurality of Yscontained may be different from one another.

More specific example of the tridentate ligand include2,4,6-tris-(4-pyridyl)-1,3,5-triazine.

As the solvent B, for example, there may be mentioned an aromaticcompound, and specific examples of the aromatic compound includenitrobenzene.

Advantageous Effects of Invention

According to the present invention, a microcrystalline powder of apolymer complex having three-dimensionally and regularly arrangedchannels can be synthesized in a much shorter time than that of thecounter diffusion method and in bulk quantity. That is, the presentinvention makes it possible to synthesize microporous polymer complexesin a short time and efficiently, which have been synthesized by taking along period of time such as one week or more. Therefore, the presentinvention is highly productive. Furthermore, the present inventiongreatly contributes to practical application of polymer complexes whichhave been expected to be used in various fields.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows diagrams showing the crystal structure and radiationdiffraction patterns of polymer complex 1.

FIG. 2 shows diagrams showing the crystal structure and radiationdiffraction patterns of polymer complex 2.

FIG. 3 shows diagrams showing the crystal structure of polymer complex1′.

DESCRIPTION OF EMBODIMENTS

The synthesis method of the present invention is characterized by that(1) a metallic solution, which is a mixture of zinc halide (II) and asolvent A that can dissolve the zinc halide, is mixed with (2) a ligandsolution, which is a mixture of a tridentate ligand that has threecoordination sites coordinated to zinc of the zinc halide and a solventB that can dissolve the tridentate ligand, to be a single-phasesolution, thereby synthesizing a microcrystal of a polymer complexhaving a three-dimensional coordination network formed by coordinatingthe tridentate ligand to the zinc and having channels that arethree-dimensionally and regularly arranged in the three-dimensionalcoordination network.

As a result of diligently studying the method of synthesizing a polymercomplex and the method of specifying the structure of a polymer complex,the present inventors have found out that as shown in FIG. 1(A), a whitepowder obtained by mixing a nitrobenzene solution of2,4,6-tris-(4-pyridyl)-1,3,5-triazine with a methanol solution of ZnI₂at room temperature and stirring the mixture for 30 seconds to be asingle-phase solution (seethe following Formula 5) consists of asingle-component polymer complex having a complexed three-dimensionalcoordination network formed by interpenetration of three-dimensionalcoordination networks 1 a and 1 b each having a plurality of2,4,6-tris-(4-pyridyl)-1,3,5-triazine (hereinafter may be referred to astpt) and ZnI₂ bound three-dimensionally to each other via coordinatebonding (see FIG. 3 (3B)).

More specifically, the inventors of the present invention have found outthat this polymer complex has a composition represented by[(ZnI₂)₃(tpt)₂(PhNO₂)_(5.5)]_(n). Furthermore, the inventors have foundout that its three-dimensional structure is isomorphic to that of singlecrystal [(ZnI₂)₃(tpt)₂(PhNO₂)_(5.5)]_(n) synthesized by some of thepresent inventors who also specified the structure of the singlecrystal, by crystal growing with a counter diffusion method using anitrobenzene solution of tpt and a methanol solution of ZnI₂. That is,the three-dimensional structure is a monoporous network structure (seeFIG. 3 and Angew. Chem. Int. Ed. 2002, 41, No. 18, pp. 3392-3395).

In addition, the inventors of the present invention have found out thatpolymer complex [(ZnBr₂)₃(tpt)₂(PhNO₂)₅(H₂O)]_(n) which has athree-dimensional coordination network isomorphic to that of the singlecrystal [(ZnI₂)₃(tpt)₂(PhNO₂)_(5.5)]_(n) can be obtained by using ZnBr₂as the zinc halide, in place of the ZnI₂ (seethe following Formula (6)).

Conventionally, there has been established no method of specifying thestructure of a polymer complex which has a three-dimensionalcoordination network and is obtained in the form of microcrystallinepowder. However, the inventors of the present invention have made itpossible to specify the higher-order structure (crystal structure) ofpowdery samples by using an analysis method such as powder X-raystructure analysis with radiation synchrotron followed by analysis ofthe resulting data with a software program such as RIETAN-FP and DASH,elemental analysis, and thermogravimetry-mass spectrometry (TG-MS). Thatis, it has been clarified by using the method which has been newlydeveloped by the present inventors for analyzing the high-orderstructure of powder samples, that the powder obtained by the synthesismethod of the present invention is microcrystals of a polymer complexhaving a three-dimensional coordination network.

The synthesis method of the present invention is to form a polymercomplex having a three-dimensional coordination network in such a mannerthat a plurality of multidentate ligands having three or morecoordination sites are instantly coordinated to tetrahedral metalspecies serving as a clasp to connect the multidentate ligands by mixingthem to be a single-phase in the presence of a template solvent whichserves as a template of channels, followed by self-organization of themultidentate ligands and tetrahedral metal species.

Unlike the counter diffusion method, the synthesis method of the presentinvention conducts synthesis by mixing the above-mentioned componentsconstituting a polymer complex for a short time to be a single-phase.[(ZnI₂)₃(tpt)₂(PhNO₂)_(5.5)], which is obtained by a typical example ofthe synthesis method of the present invention, that is, by mixing theabove nitrobenzene solution of tpt with the above methanol solution ofZnI₂ and stirring the mixture at room temperature, is synthesized in thereaction condition of 30 seconds at room temperature. Accordingly,[(ZnI₂)₃(tpt)₂(PhNO₂)_(5.5)] can be said to be a kinetically-controlledproduct. Therefore, it is possible to synthesize a kinetically-stablepolymer complex by designing or setting, for example, the reactioncondition of the polymer complex from a kinetic standpoint.

Also in the present invention, it is considered that channels of thepolymer complex are formed by a template effect caused by the solvent Bwhich dissolves the tridentate ligand in the ligand solution (2). Morespecifically, it is considered that when forming the polymer complex,the solvent which can cause a strong interaction with the tridentateligand goes into the polymer complex because of its interaction andforms a space inside the polymer complex. Then, even if the templatesolvent is removed by guest exchange after the formation of the polymercomplex, the channels are maintained. Therefore, it is possible toprecisely control the shape, size, etc. of the channels by selecting notonly the metal species and multidentate ligand which forms thethree-dimensional structure of the polymer complex, but also the solventB which dissolves the multidentate ligand.

As described above, according to the synthesis method of the presentinvention, it is possible to synthesize a polymer complex havingchannels in a short time. Although the time required for the synthesisof the polymer complex varies depending on the amount of the metallicsolution (1) and ligand solution (2) to be mixed, the mixing method, theshape of a reaction container, the reaction temperature, etc., accordingto the present invention, it is possible to synthesize a polymer complexin a second-scale mixing time within one minute to bring the metallicsolution (1) into contact with the ligand solution (2) thereby producinga microcrystal.

Because the resulting polymer complex is a single component, it ispossible to synthesis a polymer complex selectively and in bulkquantity. Moreover, it is possible to precisely control the shape, size,etc. of the channels of the resulting polymer complex by appropriatelyselecting, as aforementioned, the metal species, the ligand and thesolvent which can dissolve them.

Also, because the resulting polymer complex is powdery microcrystals, itcan be expected to be used as a microporous material which has a largesurface area and shows quick absorption performance.

Hereinafter, the synthesis method of the present invention will beexplained in detail.

In the present invention, the zinc halide is coordinated with aplurality of tridentate ligands to form a three-dimensional coordinationnetwork. Thus, the zinc halide serves as a clasp to connect thetridentate ligands. As the metal species which can serve as such aclasp, there may be mentioned one which can form a coordination bondwith a different atom at each vertex of the regular tetrahedron, thatis, one which can form a tetrahedral coordination bond.

In the present invention, zinc halide (II) is used as the tetrahedralmetal species. In particular, there may be mentioned zinc bromide(ZnBr₂) and zinc iodide (ZnI₂).

As the solvent A which dissolves the zinc halide, one may be used and isnot particularly limited as long as it can dissolve the zinc halidewhich is a metal species serving as a clasp. Preferred are alcoholswhich do not form a strong coordination bond with a metal, such asmethanol, ethanol, isopropyl alcohol and tert-butyl alcohol. The solventA may be one solvent alone, or a mixture of two or more kinds ofsolvents.

The metallic solution (1), which is a mixture of the zinc halide (II)with the solvent A, can be obtained by mixing and stirring the zinchalide (II) and the solvent A by any method to dissolve the zinc halidein the solvent A. As the method of mixing and stirring, it is onlyrequired to adopt the type or mixing ratio of the metal species andtridentate ligand to the composition ratio of a polymer complex to beproduced, and one may be used and is not particularly limited as long asit can uniformly dissolve the zinc halide in the solvent A.

As the tridentate ligand coordinated to the zinc of the zinc halide(II), one may be used and is not particularly limited as long as it hasthree coordination sites which can form a coordination bond with thezinc of the zinc halide. Multidentate ligands having four or morecoordination sites can form a polymer complex having a three-dimensionalcoordination network; however, tridentate ligands are more likely toform a kinetically-controlled reaction product.

The directions of coordination bonds formed by the three coordinationsites of the tridentate ligand are preferably present in almost the sameplane. This is because, as in this case, a regular three-dimensionalcoordination network can be formed when the vectors of the coordinationbonds formed by the coordination sites are present in the same plane.

From the viewpoint of capability to form a regular three-dimensionalcoordination network, preferred is a tridentate ligand having astructure in which the three coordination sites thereof are arrangedradially from the center of the tridentate ligand at regular intervals.Particularly preferred is a tridentate ligand having a structure inwhich three coordination sites thereof are arranged radially from thecenter of the tridentate ligand at regular intervals in almost the sameplane.

It is to be noted that the term “almost the same plane” used hereinrefers to not only the state in which the coordination sites are presentin the completely same plane, but also the state in which thecoordination sites are present in a plane which is slightly off, forexample, in a plane which intersects at an angle of 20° or less with aplane that serves as the standard. The center of the tridentate ligandrefers to the center position which is observed when looking at thetridentate ligand two-dimensionally. The state in which the threecoordination sites are arranged radially from the center at regularintervals refers to a state in which the three coordination sites areeach arranged on a line which extends radially from the center atregular intervals.

Specific examples of the tridentate ligand include an aromatic compoundrepresented by the following Formula (1):

ArX—Y)₃  Formula 1

wherein Ar is a structure having an aromatic ring; X is a divalentorganic group or a single bond through which Ar and Y are directly boundto each other; Y is a coordinating atom or a coordinatingatom-containing atomic group; and a plurality of Xs contained in onemolecule may be different from one another, and a plurality of Ys may bedifferent from one another.

In Formula 1, Ar has a π plane forming a pseudo-plane structure. Ar isnot particularly limited and may be appropriately selected byconsidering a certain influence of the molecular size of the tridentateligand on the size of a channel to be formed in the polymer complex.Specific examples of Ar include a monocyclic aromatic ring, particularlya 6-membered aromatic ring or a condensed polycyclic aromatic ring bi-to pentacyclic, particularly a condensed polycyclic aromatic ring havingtwo to five 6-membered aromatic rings condensed therein.

For easiness in synthesis, Ar is preferably a monocyclic aromatic ringsuch as a 6-membered aromatic ring. Examples of the monocyclic6-membered aromatic ring include a benzene ring, a triazine ring, apyridine ring, a pyrazine ring, etc.

Ar may be a structure having an aromatic ring, and may partially containan alicyclic cyclic structure or an endocyclic heteroatom. Ar may have asubstituent other than —(X—Y).

When X intermediating between Ar and Y in Formula 1 is a divalentorganic group, its chain length etc. may be selected appropriatelydepending on the required size etc. of a channel formed in the polymercomplex. For forming a channel that can incorporate an organic compoundhaving a relatively large molecular size, examples of X include adivalent aliphatic group having 2 to 6 carbon atoms, a 6-membereddivalent monocyclic aromatic ring, and a condensed polycyclic aromaticring having two to four 6-membered aromatic rings condensed therein.

The aromatic ring may contain an endocyclic hetero atom or may have asubstituent. The aromatic ring may partially contain an alicyclicstructure. The alicyclic group may have a branched structure, maycontain an unsaturated bond, or may contain a hetero atom.

Specific examples of the divalent organic group include a monocyclicaromatic ring such as a phenylene group, thiophenylene, or furanylene, acondensed polycyclic aromatic ring having benzene rings condensedtherein, such as a naphthyl group or anthracene, an aliphatic group suchas an acetylene group, an ethylene group, an amido group or an estergroup, and a group wherein these groups, the number of which isarbitrary, are linked to one another in an arbitrary order. A pluralityof Xs contained in one molecule may be the same or different from oneanother, but is usually preferably the same from the viewpoint of easysynthesis.

Y is a coordinating atom having a coordination site which can becoordinated to the zinc ion of the zinc halide, or an atomic groupcontaining such a coordinating atom, and is not particularly limited aslong as it can be coordinated to the zinc to form a three-dimensionalcoordination network. Examples of Y include groups represented by thefollowing Formula 2:

Formulae 2 (b), 2 (c) and 2 (d) have a resonance structure so that alone electron pair can be given to the central metal ion. Hereinafter,the resonance structure of Formula 2 (c) is shown as a typical example.

Y may be a coordinating atom itself having a coordination site, or maybe an atomic group containing a coordinating atom having a coordinationsite. For example, the above-mentioned 4-pyridyl group (2 (a)) is anatomic group containing a coordinating atom (N). From the viewpoint ofattaining suitable coordination strength upon coordination bonding tothe zinc ion via a lone electron pair possessed by the coordinating atomof Y, the pyridyl group (2 (a), 2 (f)) is particularly preferable amongthe groups of the above formulae.

The tridentate ligand is preferably an aromatic compound wherein allcoordination sites of the tridentate ligand exist in almost the sameplane. Particularly, the aromatic compound ligand when viewed as a wholeis preferably in the form of a pseudo-plane owing to its π-conjugatedsystem. That is, all Ys contained in the tridentate ligand (1)represented by Formula 1 above are preferably present in almost the sameplane. It is particularly preferable that three —(X—Y)s bound to and Arbecome unified by the π-conjugated system to form a stable pseudo-planestructure in which all Ys exist.

From the viewpoint of allowing the polymer complex to form a strongthree-dimensional structure, it is preferable that in the tridentateligand wherein Ar and three —(X—Y)s become unified by the π-conjugatedsystem to form a pseudo-plane structure, —(X—Y) has a rigid linearstructure, and in an environment intended to be used, its rotation onthe axis is restricted.

From this viewpoint, preferable examples of X among those mentionedabove include a single bond through which Ar and Y are directly bound toeach other, an aromatic group, for example a monocyclic aromatic ringsuch as a phenylene group or a condensed polycyclic aromatic ring suchas a naphthyl group or anthracene, an aliphatic group such as anacetylene group or an ethylene group, and a group wherein these groups,the number of which is arbitrary, are linked to one another in anarbitrary order. When —(X—Y) has a structure composed of an aromaticring, an acetylene group or an ethylene group or a structure havingthese groups linked therein, its axial rotation is restricted due tosteric hindrance. When the structure composed of an aromatic ring, anacetylene group or an ethylene group forms a conjugated system where πelectrons are delocalized, its axial rotation is restricted by an energybarrier of the conformation. Accordingly, the tridentate ligandsrepresented by Formula 1 can become unified to attain a pseudo-planestructure, thereby forming a stable three-dimensional coordinationnetwork.

From the viewpoint of ease in design of the polymer complex, Ypreferably has a coordination site, particularly a lone electron pair inthe extending direction of the axis of —(X—Y) having the rigid linearstructure described above. More preferably, the directions ofcoordination bonds formed respectively by these coordination sites arepresent in almost the same plane.

As the above-mentioned tridentate ligand having the structure whereincoordination sites are arranged radially at regular intervals in theextending direction of a plane formed by the π-conjugated system of thearomatic ring with the aromatic ring-containing structure Ar as thecenter, and in which the directions of coordination bonds formed bythree Ys each having a coordination site are present in almost the sameplane, there may be mentioned 2,4,6-tris-(4-pyridyl)-1,3,5-triazine(tpt) represented by the following Formula 4:

As the solvent B which dissolves the tridentate ligand, one may be usedand is not particularly limited as long as it can dissolve thetridentate ligand. Particularly in the case where an interaction occursbetween the solvent B and the tridentate ligand, the solvent B isconsidered to serve as a mold of the channels of the polymer complex.The size, shape, etc., of the channels to be formed is considered tovary depending on the solvent B used, so that it is preferable to selectthe solvent B considering the interaction with the tridentate ligand,molecular size, polarity, etc.

As the solvent B, there may be mentioned an aromatic compound. Becausethe tridentate ligand represented by the above (1), tpt or the like hasan aromatic ring, the interaction between the tridentate ligand and thesolvent B can be enhanced by using an aromatic compound as the solventB, and thus it becomes possible to form regular channels certainly.Specific examples thereof include nitrobenzene, benzene, toluene, etc.The solvent B may be one kind alone or a mixture of two or more kinds.

The ligand solution (2), which is a mixture of the tridentate ligandwith the solvent B, can be obtained by mixing and stirring thetridentate ligand and the solvent B by any method to dissolve thetridentate ligand compound in the solvent B. As the method of mixing andstirring, it is only required to adopt the type or mixing ratio of themetal species and tridentate ligand to the composition ratio of apolymer complex to be produced, and one may be used and is notparticularly limited as long as it can uniformly dissolve the tridentateligand in the solvent B.

For the purpose of concentration regulation to prevent the metal speciesor tridentate ligand from being precipitated alone in the early stage ofmixing, the ligand solution (2) may also contain the solvent A which candissolve metal species besides the solvent B. The content of the solventA is preferably 20 vol % or less with respect to the solvent B.

By instantly mixing the thus-obtained metallic solution (1) and ligandsolution (2) to be a single-phase solution, a microcrystal of a polymercomplex having a three-dimensional coordination network can be formed,in which network the tridentate ligand in the ligand solution (2) iscoordinated to the zinc of the zinc halide in the metallic solution (1),and three-dimensionally and regularly arranged channels are formed.

The method of mixing and stirring the metallic solution (1) and theligand solution (2) is not particularly limited as long as asingle-phase solution can be obtained by the method in a short time, andany method can be employed depending on the amount of synthesis, theshape of a reaction container, the reaction temperature, etc. Forexample, the total amount of the metallic solution (1) and the totalamount of the ligand solution (2) may be mixed together at once andstirred, or mixing and stirring may be performed while the metallicsolution (1) and the ligand solution (2) are continuously supplied.Alternatively, the metallic solution (1) may be divided into severallots and supplied to the ligand solution (2) to be mixed and stirredwithout deteriorating the effect of the present invention, vice versa.

The condition applied to the step of mixing the metallic solution (1)with the ligand solution (2) is not particularly limited. For example,the reaction may be performed under a mild condition of room temperature(about 10 to 30° C.).

In the manner as described above, according to the present invention, itis possible to obtain a polymer complex in the form of powderymicrocrystals by taking very simple steps and also in a short time.Furthermore, as described above, it is possible to obtain asingle-component polymer complex and, according to the synthesis methodof the present invention, it is possible to obtain a polymer complexvery efficiently.

As the method of analyzing the structure of a microcrystalline powderobtained by the synthesis method of the present invention, there may bementioned elemental analysis, thermogravimetry-mass spectrometry(TG-MS), powder X-ray crystal structure analysis, etc. By using, amongthem, powder X-ray crystal structure analysis, it has been succeeded indetermining the structure of the microcrystalline powder by measuringthe microcrystalline powder for its diffraction pattern with radiation,determining the structure of the microcrystalline powder from theresulting diffraction pattern with the use of DASH program, and inrefining the structure by performing Rietveld analysis with the use ofRIETAN-FP program.

Hereinafter, the crystal structure of polymer complex 1[(ZnI₂)₃(tpt)₂(PhNO₂)_(5.5)]_(n) will be described, which is a typicalexample of the polymer complex obtained by the synthesis method of thepresent invention, and is obtained by the reaction represented byFormula (5), that is, by mixing a nitrobenzene solution of tpt with amethanol solution of ZnI₂ at room temperature and stirring the mixturefor 30 seconds (see FIG. 1).

As described above, the polymer complex 1 is isomorphic to singlecrystal [(ZnI₂)₃(tpt)₂(PhNO₂)_(5.5)]_(n), which can be obtained bycrystal growing with a counter diffusion method using a nitrobenzenesolution of tpt and a methanol solution of ZnI₂ (see FIG. 3 and Angew.Chem. Int. Ed. 2002, 41, No. 18, pp. 3392-3395). More specifically, twokinds of three-dimensional coordination networks 1 a and 1 b, in whichZn of ZnI₂ forms a tetrahedral coordination bond with two Is and twolone electron pairs of a pyridyl group of tpt and thus isthree-dimensionally connected to them, are interpenetrated to form acomplexed three-dimensional coordination network. The three-dimensionalcoordination networks 1 a and 1 b do not have a direct or indirect bondvia which, for example, both the networks have Zn in common. The twonetworks are each an independent polymer skeleton and areinterpenetrated and nested alternately to each other so as to have thesame space in common. Then, complexes which are each formed byinterpenetration of two kinds of three-dimensional coordination networks1 a and 1 b, are continuously stacked, thereby forming a complexedthree-dimensional coordination network.

This three-dimensional coordination network has a closed circularstructure consisting of 10 tpt molecules and 10 Zn atoms as the shortestclosed circular structure, and is considered to have (10,3)-bconfiguration. Also, along (010) axis, this three-dimensionalcoordination network can be regarded as a helical and hexagonalthree-dimensional coordination network. A polymer complex formed byinterpenetration of two such three-dimensional coordination networks hasone kind of channels which penetrate these two three-dimensionalcoordination networks and are regularly arranged.

The crystal structure of the polymer complex obtained by the synthesismethod of the present invention is not limited to the above structure.

The polymer complex provided by the present invention has a function ofincorporating and/or releasing and/or transporting a guest moleculeselectively. Accordingly, separation, refinement, storage, etc., of aspecific component are made possible by using the polymer complex.

Furthermore, as mentioned above, it is possible to control the shape,size, atmosphere of the channels by molecular design, so that thepolymer complex can be expected to be effectively used for variouspurposes in a wide variety of fields.

EXAMPLES Synthesis of Polymer Complex 1

In a mixture of nitrobenzene/methanol (32 ml/4 ml), tpt of 50.2 mg wasdissolved to prepare a ligand solution. At room temperature, theobtained ligand solution was mixed with a metallic solution prepared bydissolving ZnI₂ of 76.5 mg in methanol of 8 ml, followed by stirring for30 seconds, thereby obtaining a white powder of 151.7 mg (yield: 81.6%).

The thus-obtained white powder sample was identified by elementalanalysis and thermogravimetry-mass spectrometry (TG-MS) and found to be[(ZnI₂)₃(tpt)₂(PhNO₂)_(5.5)]_(n) (polymer complex 1).

<Elemental Analysis Result>

[(ZnI₂)₃(tpt)₂(PhNO₂)_(5.5)]_(n)

Theoretical Values: C: 36.68%, H: 2.30%, N: 10.85%

Measured Values: C: 36.39%, H: 2.43%, N: 10.57%

Furthermore, powder X-ray crystal structure analysis with radiationsynchrotron was performed on the obtained white powder sample withSpring-8 (wavelength: 0.69995(2) Å). Therefore, the white powder wasfound to be monoclinic with space group C2/c and to have a latticevolume of 16140 Å³ and a nested network structure (coordination network)which had channels of a single type (see FIG. 1). Despite the polymercomplex had the large lattice volume and low symmetry, by using softwareprogram DASH, the skeleton structure of the polymer complex 1 could beprimarily obtained from the powder X-ray diffraction data thus obtained.FIG. 1 (1A) shows the crystal structure of the polymer complex 1. FIG.(1B) shows diffraction patterns of the polymer complex 1 (solid line:measured diffraction pattern, dashed line: theoretical diffractionpattern derived by simulation).

In FIG. 1 (1B), the theoretical diffraction pattern derived from thecrystal structure of the polymer complex 1 by simulation and themeasured diffraction pattern showed a good concordance therebetween, andthe residue which corresponds to the difference between the diffractionpatterns was small.

On the other hand, nitrobenzene of 4 ml and methanol of 1 ml werecharged into a test tube, and tpt of 6.3 mg was dissolved therein. Then,a solution prepared by dissolving ZnI₂ of 9.6 mg in methanol of 1 ml wasgently added thereto to form a top layer and left at about 15 to 25° C.(room temperature) for about seven days, thereby obtaining polymercomplex 1′ [(ZnI₂)₃(tpt)₂(PhNO₂)_(5.5)]_(n).

The result of X-ray crystal structure analysis of the thus-obtainedpolymer complex 1′ is shown in FIG. 3. No guest molecule is shown inFIG. 3 because it is omitted.

As a result of comparing the above-obtained crystal structure of thepolymer complex 1 (FIG. 1 (1A)) to that of the polymer complex 1′ (FIG.3 (3A)), it is clear that their three-dimensional structures areidentical.

Synthesis of Polymer Complex 2

In a mixture of nitrobenzene/methanol (32 ml/4 ml), tpt of 50.2 mg wasdissolved to prepare a ligand solution. At room temperature, theobtained ligand solution was mixed with a metallic solution prepared bydissolving ZnBr₂ of 54.0 mg in methanol of 8 ml, followed by stirringfor 30 seconds, thereby obtaining a white powder of 77.3 mg (yield:47.8%).

The thus-obtained white powder sample was identified by elementalanalysis and thermogravimetry-mass spectrometry (TG-MS) and found to be[(ZnBr₂)₃(tpt)₂(PhNO₂)₅(H₂O)]_(n) (polymer complex 2).

<Elemental Analysis Result>

[(ZnBr₂)₃(tpt)₂(PhNO₂)₅(H₂O)]_(n)

Theoretical Values: C: 40.99%, H: 2.66%, N: 12.31%

Measured Values: C: 40.96%, H: 2.83%, N: 12.08%

Furthermore, powder X-ray crystal structure analysis with radiationsynchrotron was performed on the obtained white powder sample withSpring-8 (wavelength: 1.29918(3) Å). Therefore, the white powder wasfound to be monoclinic with space group C2/c and to have a latticevolume of 15638 Å³ and a nested network structure (coordination network)which had channels of a single type (see FIG. 2). Despite the polymercomplex 2 had the large lattice volume and low symmetry, by usingsoftware program DASH, the skeleton structure of the polymer complex 2could be primarily obtained from the powder X-ray diffraction data thusobtained. FIG. 2 (2A) shows the crystal structure of the polymer complex2. FIG. (2B) shows diffraction patterns of the polymer complex 2 (solidline: measured diffraction pattern, dashed line: theoretical diffractionpattern derived by simulation).

In FIG. 2 (2B), the theoretical diffraction pattern derived from thecrystal structure of the polymer complex 2 by simulation and themeasured diffraction pattern showed a good concordance therebetween, andthe residue which corresponds to the difference between the diffractionpatterns was small.

As a result of the model calculations performed on the presumption thatthe three-dimensional structure of the polymer complex 2 was similar tothe structure of the polymer complex 1 obtained by the X-ray crystalstructure analysis, the theoretical diffraction pattern thus obtainedwas almost identical with the actually measured diffraction patternobtained in the powder X-ray crystal structure analysis, and there wasalmost no residue left which corresponds to the difference between thediffraction patterns. Therefore, the polymer complex 1 and the polymercomplex 2 are considered to have three-dimensional coordination networkswhich are isomorphic to each other.

1. A synthesis method of a polymer complex crystal wherein (1) ametallic solution, which is a mixture of zinc halide(II) and a solvent Athat can dissolve the zinc halide, is mixed with (2) a ligand solution,which is a mixture of 2,4,6-tris-(4-pyridyl)-1,3,5-triazine and asolvent B that can dissolve the 2,4,6-tris-(4-pyridyl)-1,3,5-triazine,to be a single-phase solution, thereby synthesizing a microcrystal of apolymer complex having a three-dimensional coordination network formedby coordinating the 2,4,6-tris-(4-pyridyl)-1,3,5-triazine to zinc of thezinc halide and having channels that are three-dimensionally andregularly arranged in the three-dimensional coordination network.
 2. Thesynthesis method of a polymer complex crystal according to claim 1,wherein the step of mixing the metallic solution with the ligandsolution is performed at room temperature.
 3. The synthesis method of apolymer complex crystal according to claim 1, wherein the zinchalide(II) is zinc bromide(II) or zinc iodide(II). 4-7. (canceled) 8.The synthesis method of a polymer complex crystal according to claim 1,wherein the solvent B is an aromatic compound.
 9. The synthesis methodof a polymer complex crystal according to claim 8, wherein the solvent Bis nitrobenzene.